Detachable electrical connector



p 1953 H. M. WADSWORTH 2,653,304

DETACHABLE ELECTRICAL CONNECTOR Filed June '6, 1950 i0 a 13 a 8 7 a? 3 ii INVENTOR. WITNESS A1wurd772 Mworfl A OHNEY Patented Sept. 22, 1953UNITED STATES harem OFFICE I H 7 2,653,304 7 DETACHABLE ELECTRICALCONNECTOR Howard M. Wadsworth, Liverpool, N. Y. ApplicationJune 6, 1950,Serial No. 166,318

The present invention relates toia detachable electrical connector andmore particularly to a grid cap for vacuum tubes. I

It is an object of the present invention to provide an electricalconnector which is simple and economical in construction and provides afirm, intimate contact betweenthe engaging surfaces.

It is another object to provide such a device in which the electricallycharged surfaces are entirely enclosed when the cap is applied to thegrid terminal So as to reduce the liability of corona discharges.

Another object is to provide such a device including a stamped electrodeand a molded dielectric cup having interengaging parts providing a.rigid connection while permitting the electrode to expand and contractto closely grip the cooperating terminal.

Further objects and advantages will be apparent from the followingdescription taken in connection with the accompanying drawing, in which:

Fig. 1 is a vertical substantially mid-sectional View of the dielectriccap enclosing the terminal;

Fig. 2 is a side elevation of a preferred form of terminal;

Fig. 3 is an end View of the terminal;

Fig. 4 is a vertical substantially mid-sectional view of the assembledconnector;

Fig. 5 is a view looking into the open end of the assembled connector;

Fig. 6 is a vertical substantially mid-sectional view of the connectoras assembled on the cylindrical terminal of a vacuum tube; and

Fig. 7 is a section taken substantially on the line 1-1 of Fig. 6.

Referring first to Fig. 2 of the drawing there is illustrated anelectrode l of suitable conductive material comprising a base 2, and apair of arms 3 and 4 extending substantially perpendicular to the baseand connected thereto by hinge portions 5 and 6 which render the armselastically expansible. The arms 3 and 4 are cylindrical in contour asbest shown in Fig, 3, and in the spaces between the arms, the base 2 isprovided with radially extending lugs or projections I and 8 the outercontours of which are circular. The lug 1 extends substantially in theplane of the base 2 but is slightly twisted so that the outer edge formsa portion of a screw thread. The projection 8 is similarly twisted andis offset slightly as shown in Fig. 2 so that the lugs I and 8 provideportions of a single screw thread. A cup 9 of suitable dielectricmaterial (Fig. 1) is arranged to receive the electrode l therein and 3Claims. (01. 339-217) is provided with an ternal thread It! adapted tocooperate with the thread lugs 1 and 8 of the electrode so as to permitthe electrode to .be screwed tightly against the bottom [I of the cup.The side wall l2 of the cup is cylindrical in shape and slightly largerthan the arms of the terminal so as to permit elastic expansion of thearms.

The cup 9 is provided with a cylindrical opening I3 in its side which islocated adjacent one of the thread lugs of the electrode when the latteris screwed in place in the cup as shown in Fig. 4. A cable l4 having aninsulating sheath !5 traverses the opening [3 and is rigidly attached tothe base of the electrode as by soldering as indicated at 6, so as toform a permanent electrical connection and at the same time prevent theelectrode from unscrewing. The sheath [5 of cable l4 has a press fit inthe opening l3 so as to tightly close said opening. It will beunderstood that the opening I3 in the side of the cup is preferablydrilled after the electrode has been screwed in place in the insulatingcup, the electrode being arranged to cooperate with a suitable drillingfixture so as to properly locate said opening with respect to theelectrode.

The radius of curvature of the spring arms 3, v 4 of the electrode isslightly less than the radius of the cylindrical terminal for which theconnector is designed. Thus, as shown in Figs. 6 and 7 when theconnector is pressed on to the terminal I1 of a vacuum tube I8, the armseach have two line contacts with the cylindrical surface of the terminalas shown at points l9, 2|, 22, 23 in the section illustrated in Fig. 7.This arrangement secures high unit pressure between the connector andthe terminal thus providing a clean metalto-metal contact therebetween.

Although but one embodiment of the invention has been shown anddescribed in detail it will be understood that changes may be made inthe precise design and arrangement of the parts without departing fromthe spirit of the invention.

What is claimed is:

1. A grid cap for vacuum tubes including an electrode having a flat basewith a pair of spring arms extending perpendicular thereto, said basebeing provided with a pair of thread lugs extending radially from thebase intermediate the junctions of the arms with the base; a cylindricalcup of dielectric material loosely surrounding the arms of the electrodeand having an internal thread into which the thread lugs of the base arescrewed to anchor the electrode to the bottom of the cup, said cuphaving a cylindrical radial opening in its side located adjacent one ofthe lugs of the electrode; and means for rigidly anchoring the electrodein the cup comprising an insulated cable having a press fit in saidopening extending radially across one of said lugs and rigidly attachedto the base of the electrode.

2. A high tension electrical connector for attachment to a cylindricalterminal comprising an electrode having a flat base and a pair ofelastic arms extending substantially normal to the base, a cup ofdielectric material surrounding the electrode with the rim of the cupextending substantially beyond the ends of said arms, said base having apair 'of radially extending projections located intermediate said arms,the outer con tours of which are twisted and offset to form portions ofa screw thread, said dielectric cup having an internal screw thread nearits bottom formed to receive said projections when the electrode isscrewed into the cup, said cup also having a cylindrical radial openingadjacent one of the base projections, and means for preventing theelectrode from unscrewing from the cup comprising a cable traversing theopening extending radially across one of said lugs and rigidly at- 4tached to the base of the electrode, said cable being provided with asheath of dielectric material having a force fit in said opening.

3. A high tension electrical connector as set forth in claim 2 in whichthe side wall of the cup is spaced from the arms of the electrode topermit fiexure thereof, said arms being cylindrical in shape with radiislightly les than the radius of the cylindrical terminal which theconnector is designed to fit.

HOWARD M. WADSWORTH.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,237,718 Speice Aug. 21, 1917 2,040,383 Jasper May 12, 19362,146,612 Alden Feb. 7, 1939 2,228,138 Larkin Jan. 7, 1941 FOREIGNPATENTS Number Country Date 155,066 Great Britain Dec. 16, 1920

